Problems with Poplars

robinia

robinia

Participating member
Location
Ontario, Canada
Looking for some help here.

These are three identical Populus x canescens, all the same age and planted at the same time some 30 years ago. They have had the exact same cultural, weather, soil conditions.
This year 1 of them (the middle) looks as great as always while the other 2 seem to have given up in slightly different ways.
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One pushed no leaves at all this spring, simply started to break bud and then quit.
This tree already had a large stem removed about 3 years ago but was otherwise very healthy looking last year.
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The other one pushed out purple, smallish leaves in the spring but only in half the canopy. It retained the purple leaves but has also pushed out a few small, off-color green leaves as well.
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I was surprised to see that both the sick trees had healthy green sapwood under the bark.
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Both sick trees also have these orange, felt-like patches on the lower trunk.
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Anyone know what’s going on? I had thought of both Poplar Polyvirus and Apiophagiostoma but the symptoms came on so quick – both trees looked great last year. No gradual decline.

I’ve got a few concerns from here:
Are the two trees as far gone as they appear? I have a short window to get these things down before the campus gets really busy again at the end of the month.
I’m also second guessing myself a bit just because I like these so much and don’t want to see them gone…
Most importantly I want to keep the third healthy one. Whatever has happened with the other two could infect the third one?

Thanks for any help!
 
From what we see and what you are describing it may be just extreme cold temperatures.

No organisms? No signs?
Have a look at the roots for signs.
Had a look at Pirone and Tattar and nothing came up.

Process of elimination, I guess cold injury.

If they haven't sprouted up by now, they never will.
frown.gif

Hope I'm wrong looked like nice specimens.
 
The bottom-most image has what look to be spore tendrils to me. How about Cytospora chrysosperma? Can't confirm by those pictures but that looks like an easy call. Of course, "easy" doesn't mean "correct".
 
I can't comment on the possibility of fungal diseases which sound more likely, but I have one thought that may sound far out but maybe worth a thought.

What about natural gas leak? I have no idea how common small natural gas leaks might be but its one thing I'm starting to wonder about when I'm looking for some kind of soil condition change and not seeing any signs.

I have a candidiate tree here that I think we are going to get investigated for this. If we can.

Looking in "Abiotic Disorders of Landscape Trees, U. Cal and "blleaching, blackening or bronzing of foliage..." is described.
 
I offhand have no sureshot idea but your pictures are really good and really thorough.

I've noticed that most trembling aspen trees flush out at the same time in the spring but there is a small component that flushed out a week or two later. I've actually mistaken trees for dead for them only to flush out in a week.

Did you have any frost events in the late spring? could it be that the tree that is damaged flushed out early while the others leaves were still protected within the buds?

I'm really bad at fungal disorders, not sure what the best way is to learn more. Maybe sit in on some classes.

Frax, i think that there are several examples in prominent texts about natural gas damage and that makes us think of it more often than we should. i have never seen natural gas damage and i just can't see how it could have such an even effect on a large tree like this one.

Anyway, i'd bet on whatever Kevin says because he is the smartest person on treebuzz.

v
 
Depends on the stress level, which is hard to assess. I have to say that I've never worked with that disease as such, just with the fungus. Those long tendrils are pretty characteristic of the genus Cytospora. I often try to avoid going beyond the genus name to species just because most of these groups are in serious flux. The "chryso-" in the name refers to the gold color, so it made sense for me to stick my neck out as to species.
Now, in case anyone is still reading and interested in where the "Valsa" name comes from: This fungus has distinct sexual and asexual stages. So distinct that years back, folks didn't realize that the asexual stage (the anamorph) was related to the sexual stage (the teleomorph). So, botanists/mycologists gave two different names to the one fungus! Back when I was in graduate school, the nomenclatural code was revised to say that the name of the teleomorph is the name of the "whole fungus" and that the use of the anamorph name should be discouraged.
I resisted that then and continue to resist it now, especially in a case like this (and many other ascomycetes) where this particular Valsa is encountered only rarely in nature. I've never seen it, but I've seen plenty of Cytospora. Soooooo, My preference is to use the name that describes what we see even if it an "imperfect" or anamorphic name.
OK, more than you ever wanted to know. Ropeshield is quite right with using Valsa sordida as the name. I just want to give him credit while providing some justification for Cytospora!
 
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